What is the difference between Parquet and CSV?

Parquet is a columnar binary storage format for analytics. It stores each column separately rather than each row, which makes selective reads fast and compression very effective. It carries a typed schema and underpins most data-lake tooling. CSV is a plain-text table format: one row per line, fields separated by commas, usually with a header row. It is the most widely supported data format there is, readable by every spreadsheet, database and analytics tool.

Will I lose anything converting Parquet to CSV?

Some things, yes. Parquet carries an explicit typed schema, and CSV has no way to represent types. The values themselves come across intact; the structure around them does not.

Anything to watch out for with CSV?

CSV has no formal specification, only a convention (RFC 4180). Delimiters, quoting and line endings vary between producers. Leading zeros and long numeric strings are frequently mangled by spreadsheet applications on import — a ZIP code of 01234 becomes 1234.

How is nested data handled?

CSV is strictly flat, so nested objects and arrays have to be flattened into columns or serialised into a single cell. If your data is deeply nested, CSV will lose its shape — JSON, YAML or Parquet are better targets.

What should I know about starting from Parquet?

Parquet is binary. You cannot inspect it in a text editor — you need a reader. More broadly: Parquet is a columnar binary format built for analytics. Instead of storing records row by row, it stores each column contiguously, which makes reading three columns out of two hundred dramatically faster and compresses far better because similar values sit next to each other.

When is CSV the right choice?

CSV suits: moving tabular data between tools that share nothing else; bulk import and export; large flat datasets where JSON's repeated keys would dominate. It is the wrong choice when nested or hierarchical data.

Is there a file size limit?

No hard limit — the constraint is your browser's memory. Files under 50MB convert in a few seconds. Larger files work but take longer, and a browser tab typically has 250-500MB to play with, so very large batches are better split into smaller groups.

Does this work on mobile?

Yes. The drop zone falls back to your phone's file picker, and the conversion runs on-device exactly as it does on desktop. Large files are slower on a phone because there is less CPU and memory available, but nothing about the workflow changes.

Convert Parquet to CSV

Read a Parquet file out to CSV so you can inspect or edit it without a query engine. Free, in your browser, no upload.

Drop data files to convert

JSON, YAML, XML, CSV, Parquet

Files stay on your device. Open DevTools' Network tab to verify.

Overview

Why convert Parquet to CSV

Parquet is a binary format — you cannot open it in a text editor or diff it in version control. Converting to CSV gives you something readable and greppable, at the cost of Parquet's type information and structure.

Comparison

Parquet vs CSV: what actually differs

Parquet compared with CSV across encoding, fidelity, file size and support.
Attribute	Parquet	CSV
Full name	Apache Parquet	Comma-Separated Values
Encoding	Binary	Text — editor-readable
What it preserves	Typed schema preserved; nesting supported	Flat only — no nesting, no types, no formatting
Typical size	Much smaller than CSV or JSON for the same data — often by 5-10×	Very compact for tabular data
Support	Standard in Spark, DuckDB, Pandas, BigQuery, Snowflake and Athena.	Universal. Every spreadsheet, database and BI tool imports it.

How to

How to convert Parquet to CSV

01
Drop your Parquet file
Drag one or more Parquet files onto the drop zone above, or click to browse. Files stay on your device — there is no upload step. data formats can't be reliably identified from their bytes alone, so the extension is used to work out the source format.
02
Convert to CSV
convert.now parses the Parquet and writes it out as CSV in a Web Worker, so the page stays responsive even on large files. Nothing is sent anywhere.
03
Download the result
Download the CSV file, or a zip of all of them for a batch. Filenames are preserved, with the extension changed to .csv.

Why here

Why convert.now

Private
Files stay in your browser. No upload step. Nothing for anyone to see.
Fast
No queue, no upload wait. Conversion starts the moment you drop a file.
Free
No ads. No file-count limit. No sign-up wall. Just the converter.

FAQ

Parquet to CSV: common questions

No. The Parquet to CSV conversion runs entirely in your browser. Files never leave your device, and there is no server involved in the conversion at all. Open DevTools' Network tab and run a conversion if you want to confirm it — you will see the page and its code load, and no request carrying your file.

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Last updated 27 August 2026

Why convert Parquet to CSV

Parquet vs CSV: what actually differs

How to convert Parquet to CSV

Drop your Parquet file

Convert to CSV

Download the result

Why convert.now

Parquet to CSV: common questions

Related Parquet converters